Specialized for folding and fabricating metal ductwork, the MN1 Hand Notcher makes a full 1-inch (25.4 mm) deep “V” shaped corner notch in 24-gauge (0.71 mm) galvanized or (0.61 mm) mild steel. Long-wearing, precision-ground, steel upper jaw and hardened steel stamped components feature rust-resistant nickel plate and black oxide finishes. Great for cutting Aluminum Trailer Molding during installation!